Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

Compiler Error CS1009

Unrecognized escape sequence

An unexpected character follows a backslash (\) in a string. The compiler expects one of the valid escape characters. For more information, see Character Escapes.

The following sample generates CS1009.

// CS1009-a.cs
class MyClass
{
   static void Main()
   {
      // The following line causes CS1009.
      string a = "\m";   
      // Try the following line instead.
      // string a = "\t";
   }
}

A common cause of this error is using the backslash character in a file name, as the following example shows.

string filename = "c:\myFolder\myFile.txt";

To resolve this error, use "\\" or the @-quoted string literal, as the following example shows.

// CS1009-b.cs
class MyClass
{
   static void Main()
   {
      // The following line causes CS1009.
      string filename = "c:\myFolder\myFile.txt";   
      // Try one of the following lines instead.
      // string filename = "c:\\myFolder\\myFile.txt";
      // string filename = @"c:\myFolder\myFile.txt";
   }
}
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft